media and didn't have kids old enough to worry about but even I knew about Snapchat and its risks like 5 or 6 years ago because there was a big media push about it. I think the tepid response you're getting on this topic is because it's a "we landed on the moon" type of conversation for most of us.
Law enforcement has been aware of it for a decade, but the first amendment doesn't just let government shut down platforms because some bad people use it for evil.